1. Field of the Invention
The present invention relates to a fuel cell system with a hydrogen storage tank that contains hydrogen storage alloys and a method of storing hydrogen for the fuel cell system.
2. Description of the Related Art
Configurations of hydrogen storage tanks having hydrogen storage alloys are conventionally known as means for storing and supplying of hydrogen for the fuel cells. For example, a configuration consisting of a cooling water channel so that cooling water can circulate through a fuel cell, a hydrogen storage tank, and a heat exchange module is disclosed in JAPANESE PATENT LAYING-OPEN GAZETTE No. 2001-250570. In such a configuration, when electric power is generated by the fuel cell, it is possible to heat the hydrogen storage tank with cooling water that has an elevated temperature due to the heat exchange with the fuel cell and use the heat to remove the hydrogen that is absorbed in the hydrogen storage alloy.
When hydrogen is absorbed into the hydrogen storing metal, however, the hydrogen storage alloy needs to be cooled down in order to facilitate the operation of hydrogen absorption. An additional cooling module is thus necessary to cool down the hydrogen storage alloy at the time of hydrogen absorption.